This invention relates to devices and methods for the controlled exposure or release of molecules (such as drugs), microsized secondary devices (such as sensors), or combinations thereof.
U.S. Pat. No. 5,797,898, No. 6,551,838, and No. 6,527,762, all to Santini Jr., et al., disclose microchip delivery devices which have a plurality, typically hundreds to thousands, of reservoirs in which each reservoir has a reservoir cap positioned on the reservoir over the reservoir contents. For example, the contents, which can be a quantity of chemical molecules (e.g., drugs) or smaller devices, in each reservoir are selectively released or exposed by the controlled removal of the reservoir cap. The reservoir opening mechanism may, for example, be disintegration by electrochemical oxidation or mechanical rupture.
It would be desirable to provide new and improved technology for the controlled opening, i.e., activation, of microreservoirs in microchip or other devices. For example, the activation technology preferably would operate effectively independent of its location or environment for operation. In addition, the activation technology desirably would be robust, for example, such that surface contamination of the device (e.g., at the reservoir caps) minimally, if at all, affects its release performance. A sufficiently robust or energetic activation method could also be compatible with applied coatings that might otherwise impede activation. Such coatings could be added to enhance device strength, biocompatibility, biostability, and/or hermeticity.
Furthermore, it would be advantageous to have to a convenient means for determining that a particular reservoir of a microchip device has been activated as directed. That is, that the reservoir intended to have been opened is in fact open. Such verification techniques would be highly beneficial to demonstrate release of drug molecules or other contents from the reservoirs, ensuring reliable and consistent operation. It would be further desirable, particularly if active devices have many reservoirs, to provide a simplified means for electrically addressing each of the reservoirs.